Equilibrium is said to be attained in reversible reaction when
คำตอบ
(D)
the rates of the forward and backward reactions are equal
2
An acid present in proteins is
คำตอบ
(B)
amino acid
3
The following are uses of sulphur except
คำตอบ
(E)
coating of steel to prevent rusting
4
The reaction represented by the equation NaOH(aq) + HCI(aq) → NaCI(aq) + H2O(/)
คำตอบ
(B)
is a neutralization
5
Which of the following compound is aromatic?
คำตอบ
(A)
Benzene
6
Which of the following does not affect the rate of a chemical reaction?
คำตอบ
(C)
The enthalpy change for the reaction
7
Which of the following does not affect the rate of a chemical reaction?
คำตอบ
(C)
The enthalpy change for the reaction
8
Given that 32.0g sulphur contains 6.02 x 10 23 sulphur atoms how many atoms are there in 2.70g of aluminium? {Al = 27, S =32}
คำตอบ
(C)
6.02 x 1022
9
The empirical formula of hydrocarbon containing 0. 12 mole of carbon and 0.36 mole of hydrogen is
คำตอบ
(B)
CH3
10
A salt which loses mass when exposed to air is
คำตอบ
(C)
efflorescent
11
Detergents are better than soaps for laundry because
คำตอบ
(C)
scum is precipitated when soaps are used with hard water but not with stergents
12
Which of the following is used as an anaesthetic?
คำตอบ
(B)
CHCI3
13
Which of the following types of hybridization gives rise to tetrahedral molecules?
คำตอบ
(C)
sp3
14
Which of the following is a neutral oxide?
คำตอบ
(E)
Nitrogen oxide
15
Which of the following statements is not correct?
คำตอบ
(C)
Chlorine exhibits allotopy
16
The following are uses of radioactive isotopes except for
คำตอบ
(E)
determining equilibrum positions
17
The main characteristic feature of transition metals is that they
คำตอบ
(D)
have variable oxidation states
18
The following are heavy chemicals except
คำตอบ
(E)
dyes
19
What quantity of silver is deposited when 96500C of electricity is passed through a solution containing silver ions? (Ag = 108, 1F = 96500C)
คำตอบ
(E)
108g
20
Bubbling of carbon (IV)oxide into calcium hydroxide solution results in the formation of
คำตอบ
(A)
CaCO3
21
Which of the following is not decomposed by heat?
คำตอบ
(D)
Na2CO3
22
Which of the following is not true of the rusting of iron?
คำตอบ
(A)
Rusting is a reduction process
23
Which of the following is not true of the rusting of iron?
คำตอบ
(A)
Rusting is a reduction process
24
What volume of oxygen will be left unreacted when a mixture of 100cm3 of hydrogen and 200cm,sup>3,/sup> of oxygen are exploded in a eudiometer?
คำตอบ
(C)
150cm3
25
How many isomers can be obtained from C4H10?
คำตอบ
(C)
2
26
Water gas is a mixture of?
คำตอบ
(E)
CO and H2
27
Which of the following metals cannot extracted from its ore by using carbon (ll) oxide as the reducing agent?
คำตอบ
(C)
Al
28
Which of the following is not a naturally occurring iron ore?
คำตอบ
(A)
FeCl2
29
Which of the following equations represents the reaction of chlorine with hot concentrated sodium hydroxide solution?
คำตอบ
(C)
6NaOH + 3CI2 → NaCIO3 + 5NaCI + 3H2O
30
Aqueous sodium trioxocarbonate (IV) solution is alkaline because
คำตอบ
(E)
sodium triocarbonate (IV) is hydrolysed in water
31
Which of the following correctly explains why iodine crystals change directly into the gaseous state when heated?
คำตอบ
(C)
lodine molecules are held together by weak forces
32
Which of the following is a waste product in the Solvary Process for the manufacture of sodium trioxocarbonate (IV)?
คำตอบ
(E)
Calcium chloride
33
When copper (ll) chloride solution is treated with excess aqueous ammonia, a deep blue solution results This is due to the presence of
คำตอบ
(E)
[cU(NH3)4] ions
34
The complex salt formed when aluminium dissolves in sodium hydroxide solution is
คำตอบ
(E)
NaAI(OH)4
35
The reaction represented by the equation C(s) + H2O(l) → CO(s) + H 2(s) was carried out at 27oC if the enthalpy change was + 4500 J and the entropy change was + 12J, what was the free energy change? (∆G = ∆H - T∆S)
